Systems Research and Architecture Group (SRA)
Our Research and Teaching activities are centered around the architecture of computing systems: From hardware over system software up to languages and compilers with a focus on constructive methods for the design and development of adaptable and versatile system software. The group is led by Prof. Daniel Lohmann.
EmbeddedThose machines that are closest to our everyday life are special-purpose systems embedded into the physical world. Due to this embedding, we know a lot about the surroundings of a system. We exploit this knowledge in the design of hardware and system software.
TailoredThe requirements for every system are special. However, we often favor unspecific general-purpose components over special-purpose solutions. With the techniques of automatic tailoring, we can achieve specialized systems at moderate development costs.
SystemsDuring the architectural design, the required functionalities are often well understood. Nonfunctional aspects are decisive for choosing a system for a given task. Especially for embedded systems, we can optimize various aspects towards the given application scenario.
Oskar Pusz presents Data-Flow–Sensitive Fault-Space Pruning for the Injection of Transient Hardware Faults at the Conference on Languages, Compilers and Tools for Embedded Systems (LCTES '21).
In the paper, we describe Data-Flow–Sensitive Fault-Space Pruning (DFP), a new precise and fault-space–complete data-flow sensitive fault-space pruning method that extends on def/use-pruning by also considering the instructions’ semantics when deriving fault-equivalence sets. In our experimental evaluation, this already reduces the number of necessary injections by up to 18 percent compared to def/use pruning.
The DFP is the core element in the ISA level of our research project CLASSY-FI.
The source code and evaluation artifacts are available here: Source Code and Evaluation Data for the Paper: Data-Flow–Sensitive Fault-Space Pruning for the Injection of Transient Hardware Faults.
Björn Fiedler presents our paper ARA: Static Initialization of Dynamically-Created System Objects at the 27th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS '21).
In the paper, we present ARA, a framework for static specialization of operating systems for embedded systems. ARA is capable to statically detect operating-system objects dynamically created during run-time and replace them by statically prepared equivalents. ARA is a major building block of our reserch project AHA towards the goal to fully automatically analyze and specialize applications and their system software.
The presentation videos, source code and evaluation artifacts are available at the paper's details page: ARA: Static Initialization of Dynamically-Created System Objects
After many fruitful years with dozen of papers, great lectures and a lot of fun together, Christian Dietrich leaves our group to start his Juniorprofessorship (W1-TT-W3) with a new operating system group at TUHH. We will continue our work together, nevertheless miss him a lot, and wholeheartedly congratulate Prof. Dr.-Ing. Christian Dietrich for this great step in his career!
Christian Dietrich receives an award for the best doctoral thesis in the field of operating systems. The award is granted annually by the SIG on Operating Systems of the German Computer Assiciation (GI Fachgruppe Betriebssysteme) solely on the base of scientific excellence. It includes a price money of 500 €. Congrats, Christian!
In his dissertation Interaction-Aware Analysis and Optimization of Real-Time Application and Operating System, Christian designs and implements a control-flow--sensitive whole-system view and analysis on the interactions within real-time systems. With this approach, he can overcome many inefficiencies that arise from analyses that have an isolating focus on individual system components. Furthermore, the interaction-aware methods keep close to the actual implementation, and therefore are able to consider the behavioral patterns of the finally deployed real-time computing system.
Ralf Ramsauer presents The Sound of Silence: Mining Security Vulnerabilities from Secret Integration Channels in Open-Source Projects at CCSW '20 – due to Corona by video. In the paper, which has already been featured The Register and golem.de (German), we describe an approach to automatically detect patches that fix critical security issues before they are rolled out in the wild. We detect these patches (using the technology we described in our ICSE '19 paper) by the mere fact that they are not discussed on the mailing list. We analyzed the seven months before the release of Linux 5.4 and found commits that address 12 vulnerabilities. For these vulnerabilities, our approach resulted in a temporal advantage of 2 to 179 days to design exploits before public disclosure takes place.
Florian Rommel presents our paper From Global to Local Quiescence: Wait-Free Code Patching of Multi-Threaded Processes at OSDI '20 – due to Corona by video.
In the paper, we present WfPatch, a wait-free approach to inject code changes into running multi-threaded programs. Instead of having to stop the world before applying a patch, WfPatch can gradually apply it to each thread individually at a local point of quiescence, while all other threads can make uninterrupted progress.
WfPatch is the first outcome of our novel concept on adaptable thread-level address spaces, which we are investigating in the ATLAS project.